15 Fakultätsübergreifend / Sonstige Einrichtung

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/16

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1986 - 19872

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Institute: search.filters.UBSInstitut.Sonstige EinrichtungAuthor: search.filters.author.Döhler, Klaus-Dieter

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    Effects of adult or perinatal hormonal environment on ultradian rhythms in locomotor activity of laboratory LEW/Ztm rats
    (1986) Wollnik, Franziska; Döhler, Klaus-Dieter
    Four experiments were performed with male and female rats of the inbred strain LEW/Ztm maintained under a light-dark schedule of 12:12 hours. The animals were subject to castration (GOX) or ovariectomy (OVX), estradiol 17β-implantation (E2-capsules), and perinatal hormonal treatments with testosterone propionate (TP) and an androgen antagonist (acetate, CA). Results indicated a difference in the locomotor activity pattern between the two sexes as a result of the endogenous estradiol levels of the adult animals. The activity pattern of male LEW rats was characterized by ultradian rhythms of 4 and 4.8 hr periods. The female LEW rats, on the other hand, generally exhibited a clear circadian activity pattern and no ultradian activity rhythms. Following ovariectomy, each of the females showed distinct ultradian rhythms. These disappeared after E2-implantation. Castration of adult males had no effect on the ultradian activity pattern. Implantation of E2-capsules resulted in a marked decrease of the ultradian activity components. Perinatal treatment of the males with an androgen antagonist (CA) did not appear to effect ultradian rhythms during adulthood. Females treated perinatally with testosterone showed a significant increase in the ultradian activity components. This effect is assumed to be due to low estrogen levels in these animals during adulthood. Our study supports the assumption that ultradian rhythms are a result of changes in the phase relationships between several circadian oscillators. The synchrony of these oscillations seems to be facilitated by estradiol.
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    Neonatal sex reversal of the brain and the urinary excretion of sex dependent proteins (SDP) in the rat
    (1987) Alt, Jeannette; Jarzab, Barbara; Wollnik, Franziska; Döhler, Klaus-Dieter
    In contrast to females adult male rats excrete a variety of low molecular weight sex dependent urinary proteins (SDP). Electrophoretic separation of these proteins yields at least 8 protein bands which are arranged in typical patterns. The present study was performed to investigate the effert of sexual differentiation, which can be influenced by neonatal hormone treatment, on production and excretion of the individual SDP-bands (I - VIII). Two major groups of rats were studied: one group was neonatally treated with testosterone propionate (TP, females) or cyproterone acetate (males). Another group of rats with or without neonatal TP-treatment were gonadectomized in adulthood and subsequently implanted with TP. The results demonstrated that SDP excretion is mainly related to the circulating plasma testosterone levels. The sexual differentiation of the brain, however, influences the quantity of SDP excreted which is especially evident for bands I and II. Neonatal cyproterone had influence on these two bands only. The results demonstrate that the hormonal mechanisms regulating tho excretion of SDP varies in respect to the different protein bands. The functional role of sexual brain differentiation on the excretion of SDP and the detailed mechanisms by which the brain may control this extcretion remain to be determined.